Cervical cancer and HPV: the basics
Although cervical cancer is highly preventable, approximately 530,000 women develop the disease each year worldwide and some 270,000 die from it unnecessarily.1
More than 99 percent of cervical cancers are caused by a persistent high-risk human papillomavirus (HPV) infection, therefore screening for HPV can help identify women at risk. An important prevention strategy for women at risk is to manage their care at the pre-cancer stage, before an HPV infection progresses further, before cancer develops.2
Over the decades, many countries have adopted the Papanicolaou test (“Pap smear”) that uses a cervical cytology sample to screen women for the presence of abnormal cells which enable the diagnosis and treatment of precancerous lesions. This approach has helped reduce the number of women affected by, or who die from, cervical cancer by at least 80% in the last seventy years.3
Although the incidence of the disease has been greatly reduced since the advent of the Pap test, data reveal limitations, including difficulties in detecting precancerous cells among many normal cells and the subjective interpretation of the test, as well as inadequate sample collection.4 Consequently, up to one third of cervical cancers occur in women who have had normal Pap results.5,6
Not every woman who tests positive for high-risk HPV has or will develop cervical cancer. HPV is a common virus that can be transmitted through direct skin-to-skin contact during sexual activity with an infected individual. Approximately 80 percent of women (and men) will have had an HPV infection by age 50.7 Men and women affected often do not show symptoms and are unaware that they may be passing it on to others.8,9
More than 90 percent of all HPV infections are cleared by the body’s immune system within two years without causing any serious health problems.10
There are more than 100 types of HPV and at least 13 are high-risk for cervical cancer.2 Seventy percent of cervical cancer cases are caused by two specific genotypes – HPV 16 and 18. While there is no cure for an HPV infection, it is possible to stop disease progression and treat pre-cancer or cancer.2
Value of HPV DNA testing in preventing cervical cancer
Since the Pap smear was introduced in the 1940s, screening technologies have advanced greatly. Innovative molecular biological testing based on HPV DNA, including HPV 16/18 genotyping, immunocytochemical and immunohistochemical staining, provide the ability to identify women with the greatest risk of developing cervical cancer,11-13 those who need immediate management, and those who can safely return to routine screening.
In a meta-analysis of more than 60,000 women, high-risk HPV testing was substantially more sensitive in detecting cervical disease than Pap cytology (96.1% vs 53.0%).14
Preventive practice is evolving in parallel with technological advancements, and medical guidelines currently vary from country to country in their approaches to cervical cancer screening. In the current U.S. screening guidelines, HPV testing used in addition to a Pap test is now preferred over a Pap test alone for women aged 30-65.15 The FDA also has approved the cobas® HPV primary screening test to be used as a stand-alone option.16
Roche has an ongoing commitment to provide optimum screening and testing to protect women from cervical cancer. The Roche Diagnostics cervical cancer portfolio assists along the continuum of care, enabling physicians to screen and diagnose patients and make more prudent treatment decisions, while supporting laboratories and healthcare providers combat cervical cancer.
As HPV testing becomes integrated into primary cervical cancer screening in many countries, even greater numbers of women will be protected from this disease. By finding and treating precancerous lesions early, clinicians can prevent cancer from developing.